DES MOINES—Mitt Romney unveiled a new line of attack against President Barack Obama Tuesday, accusing his Democratic opponent of backing a plan that would “gut welfare reform.”

In a new television ad, Romney accuses Obama of “dropping work requirements” passed as part of President Bill Clinton’s 1996 welfare overhaul in favor of simply passing out checks.

“Under Obama’s plan, you wouldn’t have to work and wouldn’t have to train for a job,” the Romney ad says. “They just send you your welfare check.”

The 30-second spot, which is being jointly paid for by the Romney campaign and the Republican National Committee, references a directive issued last month by the Department of Health and Human Services that aims to give states more flexibility in approving welfare applicants.